The present invention relates to a process for synthesizing a nanostructured composite material and to an implementation device associated with this process. The device (100) comprises a chamber (3) for synthesizing said material comprising a system (13, 13a, 13b) for depositing the matrix on a target surface (15); a system (1, 4, 5, 9) for generating a jet of nanoparticles in a carrier gas comprising an expansion chamber (1) equipped with an outlet orifice (7) for the nanoparticles toward the synthesis chamber (3, 3') and, in addition, means (21, 22, 23) for adjusting the distance L between the outlet orifice (7) of the expansion chamber and the target surface (15).